NN 


2 

245 


s 

CONNECTICUT  nca^S" 

Agricultural  Experiment  Station 

NEW  HAVEN,  CONN. 


BULLETIN  245  FEBRUARY,  1923 


Results  of  Dusting  Versus  Spraying 

in  Connecticut  Apple  and  Peach 

Orchards  in  1922 

By  M.  P.  Zappe  and  E.  M.  Stoddard. 


CONTENTS 


Page 

Apple   Orchards    229 

Materials  Used   ' 230 

Apparatus  Used   230 

Method  of  Recording  Data 230 

Orchard  No.   I    231 

Orchard  No.  II 233 

Orchard  No.  Ill   236 

Orchard  No.  IV 240 

Peach  Orchards    242 

Results  of  Treatment  in  Peach  Orchard  No.  I  242 

Results  of  Treatment  in  Peach  Orchard  No.  II  242 

Summary     243 


The  Bulletins  of  this  Station  are  mailed  free  to  citizens  of  Connecticut 

who  apply  for  them,  and  to  other  applicants  as  far 

as  the  editions  permit. 


CONNECTICUT  AGRICULTURAL  EXPERIMENT  STATION 

OFFICERS  AND  STAFF 
February,   1923. 


BOARD  OF  CONTROL. 

His  Excellency,  Charles  A.  Templeton,  ex-officio,  President. 

James  H.  Webb,  Vice-President Hamden 

George  A.  Hopson,  Secretary  Mount  Carmel 

E.  H.  Jenkins,  Director  and  Treasurer New  Haven 

Joseph  W.  Alsop Avon 

Charles  R.   Treat   Orange 

Elijah    Rogers     Southington 

Edward  C.  Schneider    '. Middletown 


Administration. 


Chemistry. 

Analytical  Laboratory. 


Biochemical 
Laboratory. 

Botany. 


Entomology. 


Forestry. 


Plant  Breeding. 

Tobacco  Sub-station 
at  Windsor. 


=  Assistant  Chemists. 


STAFF. 

E.   H.  Jenkins,  Ph.D.,  Director  and  Treasurer. 

W.   L.    Slate,   Jr.,   B.Sc,    Vice-Director. 

Miss  L.  M.  Brautlecht,  Bookkeeper  and  Librarian. 

Miss  J.  V.  Berger,  Stenographer  and  Bookkeeper. 

William   Veitch,   In   charge   of  Buildings  and   Grounds. 

E.  M.  Bailey,  Ph.D.,  Chemist  in  Charge. 

R.   E.   Andrew,   M.A. 

C.  E.   Shepard 

Owen  L.  Nolan 

Harry  J.  Fisher,  A.B. 

Frank  Sheldon,  Laboratory  Assistant. 

V.  L.  Churchill,  Sampling  Agent. 

Mrs.  B.  P.  Storrs,  Clerk. 

T.  B.  Osborne,  Ph.D.,  Sc.D.,  Chemist  in  Charge 

G.  P.  Clinton,  Sc.D.,  Botanist  in  Charge. 

E.  M.  Stoddard,  B.S.,  Pomologist. 

Miss  Florence  A.   McCormick,   Ph.D.,   Pathologist. 

G.  E.  Graham,  Assistant. 

Mrs.  W.  W.  Kelsey,  Secretary. 

W.  E.  Britton,  Ph.D.,  Entomologist  in  Charge;  State  Ento- 
mologist. 
B.  H.  Walden,  B.Agr.,    M.  P.  Zappe,  B.S.,  ^Assistant 
Philip  Garman,  Ph.D.,  f     Entomologists 

John  T.  Ashworth,  Deputy  in  Charge  of  Gipsy  Moth  Work. 
Samuel  T.  Sealy,  Deputy  in  Charge  of  Mosquito  Control. 
Miss  Gladys  M.  Finley,  Stenographer. 

Walter  O.  Filley,  Forester  in  Charge. 

A.  E.  Moss,  M.F.,  Assistant. 

H.  W.  Hicock,  M.F.,  Assistant. 

Miss  Pauline  A.  Merchant,  Stenographer. 

Donald  F.  Jones,  S.D.,  Plant  Breeder  in  Charge. 
P.  C.  Mangelsdorf,  B.S.,  Assistant. 

G.  H.  Chapman,  Ph.D.,  in  Charge. 


Results  of  Dusting  Versus  Spraying  in  Con- 
necticut Apple  and  Peach  Orchards  in  1922. 

By  M.  P.  Zappe  and  E.  M.  Stoddard. 

This  series  of  experiments  with  dust  in  comparison  with  liquid 
sprays  for  controlling  the  common  insect  and  fungous  pests 
of  apple  orchards  in  Connecticut  was  begun  in  1920.  The  results 
of  that  year's  work  were  printed  in  the  Station  Report  for  1920, 
pages  168-177.  In  1921  the  project  was  enlarged  to  include 
peaches.  Four  apple  and  two  peach  orchards  were  used  and  the 
results  of  the  work  published  in  Bulletin  235  of  the  Station,  and 
in  Crop  Protection  Digest  No.  2,  page  7.  In  1922  the  same  or- 
chards were  used  as  in  preceding  years. 

APPLE    ORCHARDS.  ) 

Orchard  No.       I.     Young  orchard,    Station   Farm,   Mount 

Carmel    96  trees 

Orchard  No.     II.     Orchard  of  W.  F.  Piatt,  Orange 62  trees 

Orchard  No.  III.     Orchard  of  F.  N.  Piatt,  Milford 285  trees 

Orchard  No.   IV.     Old     orchard,     Station     Farm,     Mount 

Carmel    40  trees 

483  trees 

A  portion  of  the  dusting  materials  was  furnished  gratis  to  Dr. 
W.  E.  Britton,  Entomologist  of  this  Station,  on  behalf  of  the  Crop 
Protection  Institute  by  the  Dosch  Chemical  Company  of  Louis- 
ville, Kentucky,  and  we  hereby  express  our  appreciation  and 
thanks  for  this  favor. 

We  also  desire  to  express  our  appreciation  and  thanks  to 
Messrs.  W.  F.  Piatt  and  F.  N.  Piatt  for  the  use  of  their  orchards 
and  spray  outfits,  also  for  their  co-operation  in  this  work.  We  also 
wish  to  thank  Dr.  B.  A.  Porter,  in  charge  of  the  Wallingford  Field 
Station  of  the  Bureau  of  Entomology,  for  the  use  of  the  dusting 
machine  and  for  his  assistance  in  scoring  the  fruit.  Mr.  G.  E.  Gra- 
ham of  the  Botanical  Department  of  this  Station  assisted  in  ap- 
plying the  treatments  and  scoring  fruit.  Messrs.  W.  E.  Britton,  B. 
H.  Walden  and  P.  Garman  of  the  Entomological  Department,  and 
Messrs.  F.  D.  Luddington  and  J.  L.  Rogers,  temporary  employees, 
assisted  in  gathering  and  scoring  the  fruit.     The  owners  of  the  Or- 


230  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  245. 

chards  furnished  spray  outfits  with  team  and  driver  for  each  of 
the  spray  applications  in  orchards  II  and  III. 

MATERIALS   USED. 

SPRAYS. 
The  liquid  spray  for  all  treatments  in  all  orchards  was  as  follows : 

Commercial  Lime-Sulphur   3  gallons 

Lead  Arsenate  (Dry)    ; 3  pounds 

Nicotine  Sulphate    24  pint 

Water 100  gallons 

DUSTS. 

Sanders  or  Copper  Dust. 

Dehydrated  Lime 79  per  cent. 

Dehydrated  Copper  Sulphate 13  per  cent. 

Calcium  Arsenate 8  per  cent. 

Sulphur-Nicotine-Arsenate  Dust. 

Superfine  Dusting  Sulphur  65  per  cent. 

Lead  Arsenate    10  per  cent. 

Nicotine   Sulphate    5  per  cent. 

Carrier    20  per  cent. 

90-10  Sulphur-Arsenate  Dust. 

Dusting  Sulphur 90  per  cent. 

Lead  Arsenate    10  per  cent. 

APPARATUS  USED. 

The  dusting  machine  used  in  all  the  orchards  was  a  Niagara 
duster  owned  by  the  Bureau  of  Entomology  and  used  at  its  Field 
Station  at  Wallingford,  Connecticut.  The  machine  was  designed 
to  be  drawn  by  a  team  of  horses,  but  this  method  was  too  slow 
when  moving  the  outfit  from  orchard  to  orchard,  so.  the  machine 
was  mounted  on  a  Ford  ton  truck,  thus  saving  considerable  time 
on  the  road  and  in  the  orchards.  The  Ford  truck  had  no  trouble 
in  carrying  this  outfit  through  the  orchards.  When  the  machine 
was  not  in  use  it  could  easily  be  unloaded  from  the  truck  and 
stored  in  a  shed.  In  orchard  No.  I,  an  Arlington  X.  L.  power 
sprayer  with  a  100  gallon  tank  was  used.  Two  lines  of  hose  were 
used  with  a  nozzle  at  each  rod.  In  orchards  No.  II  and  III,  Friend 
power  sprayers  with  200  gallon  tanks  were  used.  In  orchard  No. 
II,  spray  rods  were  used,  one  man  spraying  from  the  tower  and 
the  other  from  the  ground.  The  pressure  was  about  200  pounds. 
In  orchard  No.  Ill,  a  single  line  of  hose  with  a  "spray  gun"  carry- 
ing 175  pounds  pressure  was  used,  spraying  from  the  ground. 

METHOD   OF  RECORDING   DATA. 

Certain  trees  promising  a  crop  situated  inside  the  border  of 
each  plot  and  representing  the  chief  varieties  upon  which  the  tests 


RESULTS  OF  DUSTING  VERSUS  SPRAYING  IN  CONNECTICUT.     23 1 

were  made  in  each  orchard  were  selected  and  marked  as  count 
trees.  As  a  rule  the  count  trees  were  selected  near  the  center  of 
each  plot  and  not  adjacent  to  a  plot  having  a  different  treatment 
on  account  of  the  danger  of  spray  or  dust  getting  on  the  trees 
that  were  not  intended  to  be  so  treated.  With  the  liquid  spray 
there  is  less  danger  of  this,  but  the  dust  is  quite  apt  to  drift. or  be 
blown  upon  adjoining  trees. 

The  green  dropped  fruit  from  each  of  the  count  trees  was  gath- 
ered, counted  and  examined  for  insect  and  fungous  injuries  and 
the  data  recorded  for  each  tree  twice  before  the  ripe  fruit  was 
picked.  At  harvest  time  the  picked  fruit  was  scored  in  the  same 
manner.  Each  individual  apple  was  carefully  examined  and  a 
record  made  of  each  insect  and  fungous  injury.  Apples  that  were 
called  "good"  were  absolutely  free  from  any  signs  of  insects  or 
fungous  diseases  and  might  better  be  called  "perfect",  for  they 
were  free  from  pests  and  were  perfect  except  possibly  as  to  size. 
An  apple  showing  the  work  of  more  than  one  pest  would  be 
checked  as  many  times  as  there  were  kinds  of  insect  injury  or 
fungous  diseases.  This  very  often  gave  a  greater  number  of  injur- 
ies than  there  were  apples,  and  in  order  to  get  the  true  amount  of 
any  kind  of  injury  all  the  apples  had  to  be  counted,  and  this  num- 
ber used  to  compute  the  percentage  of  injury  or  the  percentage  of 
good  fruit.  This  scoring  of  the  fruit  involved  examining  separate- 
ly 181,036  individual  apples,  equivalent  to  about  402  barrels. 

The  figures  given  in  the  tables  of  results  from  the  various  plots 
are  percentages  of  perfect  fruit  or  of  injuries  even  if  very  slight, 
and  cannot  be  compared  with  any  commercial  grading.  For  in- 
stance, an  apple  that  had  been  bitten  by  a  curculio  might  only  have 
one  or  two  small  blemishes  and  would  be  counted  as  a  "curculio" 
apple,  but  in  a  commercial  grading  of  the  fruit  would  easily  go  as 
a  No.  1  apple.  The  same  is  true  of  other  injuries,  especially  small 
spots  of  scab,  sooty  blotch  or  fruit  speck.  After  scoring  the  apples 
by  the  above  method,  all  the  fruit  on  the  count  trees  was  graded 
as  it  would  be  for  market.  The  results  obtained  by  the  commercial 
grading  method  are  of  the  greatest  importance  to  the  fruit  grower, 
and  tell  at  a  glance  which  treatment  gives  the  highest  per  cent,  of 
No.  1  fruit.  The  other  method  of  scoring  is  of  value  in  showing 
just  where  certain  treatments  fail. 

ORCHARD    NO.    I. 

Orchard  No.  I  was  the  eleven  year  old  Experiment  Station  or- 
chard located  at  Mount  Carmel.  This  orchard  is  just  begining  to 
bear,  and  consists  of  96  trees  on  a  side  hill  sloping  to  the  west.  All 
trees  bearing  fruit  were  used  as  count  trees  to  check  up  results. 
The  varieties  were  Baldwin,  Rhode  .  Island  Greening,  Roxbury 
Russet,  Mcintosh,  Gravenstein,  Duchess  of  Oldenburg,  Fall  Pip- 


232  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  245. 

pin,  Northern  Spy,  Sutton  Beauty,  King,  Wealthy,  Hurlbut  and 
Stark. 

This  orchard  was  divided  into  three  plots.  The  north  plot  was 
treated  with  liquid  spray  and  the  south  plot  with  the  90-10  sul- 
phur dust.  The  remaining  plot  in  the  center  of  the  orchard  was 
used  as  a  check. 

The  green  dropped  fruit  was  gathered,  counted  and  scored 
twice  during  the  summer.  At  harvest  time  all  the  picked  fruit  was 
scored.  All  trees  that  bore  fruit  were  used  as  count  trees  in  this 
orchard. 

NUMBER  AND  DATES   OF  APPLICATIONS. 

The  first  application  of  spray  and  dust  was  given  this  orchard 
on  April  29,  when  the  blossom  buds  began  to  show  pink.  The 
second  application  was  the  calyx  spray,  made  on  May  22.,  just  after 
all  the  petals  had  fallen.  The  next  treatment  was  given  on  June 
14.  To  test  the  value  of  later  applications  of  spray  and  dust,  the 
plots  were  each  divided  into  two  equal  parts.  One  half  of  each 
original  plot  received  two  more  applications  of  spray  and  dust 
while  the  other  half  had  no  further  treatment.  The  two  later  ap- 
plications were  made  on  June  30  and  July  20.  The  spray  and 
dust  were  always  applied  on  the  same  day.  The  dust  was  put  on 
first,  very  early  in  the  morning  before  the  wind  began  to  blow  and 
often  while  the  trees  were  still  wet  with  dew.  Later  in  the  day,  or 
as  soon  as  the  dusting  operations  were  finished,  the  liquid  spray 
was  applied.  As  there  were  no  sucking  insects  present,  nicotine 
sulphate"  was  omitted  from  the  last  two  sprayings. 

Table  No.  I. 
Results  of  Treatment.    All  Varieties. 


J3 

to 

4J 

c 

0 

C 

bo* 

,2  v 

O 
bo  C 

.2  c 

■3  " 

0 

V 

m     • 

M  S 

c 

QJ 

60 

c 

3*S 

ft  c 

V 

TjU 

,2U 

MO 

=  u 

3" 

fcu 

„u 

O    u 

•S.1- 

T3  u 

t3  u 

-  s- 

A    L- 

nl  1- 

•a  u 

Treatment. 

O    V 

Oft 

<ft 

ftft 

Oft 

3  <u 
Uft 

Oft 

0  V 
Cflft 

4->  0 

Oft 

Spray,  _ 

5    applications    . .  . 

J5-2 

18.85 

O 

I.I 

71.9 

1.9 

H-59 

2.8 

Sul.-Nic.-Ars.  Dust, 

5    applications    . .  . 

15-2 

12.49 

■054 

2.8 

80.4 

2.9 

2.06 

5-3 

1.49 

177 

.199 

20.4 

95- 

6.5 

8.9 

55-i 

Spray, 

3    applications    .... 

17.7 

II-3 

0 

2.6 

70.5 

2.9 

10. 1 

5-4 

Sul.-Nic.-Ars.  Dust, 

3    applications    . .  . 

11.05 

17.6 

.047 

4-3 

81.7 

3-3 

5-68 

10.3 

DISCUSSION    OF   RESULTS. 


In  this  orchard  there  were  many  varieties,  some  of  which  were 
represented  by  only  a  few  trees,  so  that  each  variety  could  not  be 


RESULTS  OF  DUSTING  VERSUS  SPRAYING  IN  CONNECTICUT.     233 

included  in  each  plot.  For  instance,  the  Mcintosh  variety  was  in- 
cluded only  in  the  sprayed  plots ;  none  in  the  dust  plots.  There 
were  no  varieties  that  scab  badly  in  either  of  the  dust  plots ;  there- 
fore the  percentage  of  scab  in  the  sprayed  plot  is  naturally  higher 
than  in  the  dusted  plots.  The  percentage  of  good  fruit  in  this  or- 
chard was  very  low  on  account  of  the  great  abundance  of  curculio 
injury.  In  nearly  every  case  the  liquid  spray  was  a  little  better 
than  the  dust  treatment.  The  plot  receiving  the  dust  treatment  was 
much  better  than  the  check  or  untreated  plot.  In  the  column 
called  "other  insects"  are  included  chewing  insects  which  are  nor- 
mally controlled  by  arsenate  of  lead.  The  "other  fungi"  column 
includes  sooty  blotch,  fruit  speck,  bitter  rot  and  cedar  rust.  The 
injury  from  red  bugs  in  this  orchard  was  negligible. 

FIVE   TREATMENTS   VERSUS   THREE   TREATMENTS. 

In  most  cases  the  spray  or  dust  plots  having  five  applications 
gave  a  lower  percentage  of  insect  and  fungous  injury  than  the 
plots  having  but  three  applications,  exceptions  being  the  case  of 
curculio  injury  in  the  spray  plots,  the  good  fruit  in  the  sprayed 
plots,  the  scab  results  in  both  spray  and  dust  plots,  and  aphis  re- 
sults in  both  sprayed  and  dusted  plots.  In  the  case  of  scab  results 
the  difference  is  easily  explained.  The  scab  susceptible  varieties 
were  not  equally  represented  in  the  various  plots,  there  being  more 
varieties  that  scab  easily  in  the  sprayed  than  in  the  dusted  plots. 
The  spray  plot  having  the  extra  treatments  was  on  the  northern 
edge  of  the  orchard  and  it  is  a  common  occurrence  for  the  trees 
along  the  border  of  an  orchard  to  show  greater  curculio  injury 
than  trees  further  back  from  the  margin.  The  curculio  injury  is 
caused  early  in  the  season,  soon  after  the  young  fruit  has  set,  so 
that  the  later  treatments  would  have  no  effect  on  this  insect.  The 
extra  treatments  showed  a  little  better  codling  moth  control,  evi- 
dently on  the  second  brood  worms.  The  "other  insects"  being  later 
feeders  on  the  surface  of  fruit,  would  naturally  be  better  controlled 
by  later  treatments  of  spray  or  dust.  The  'same  is  true  of  the 
fungi  which  make  their  appearance  later  in  the  season,  with  the 
exception  of  scab. 

ORCHARD  NO.    II. 

This  orchard  is  owned  by  Mr.  W.  F.  Piatt,  located  in  the  town 
of  Orange,  near  the  Milf ord  line.  It  is  twenty-eight  years  old  and 
has  been  kept  in  very  good  condition.  There  were  three  experi- 
mental plots  in  this  orchard ;  the  spray  plot,  consisting  of  33  trees ; 
the  dust  plot  of  25  trees,  and  the  check  plot  of  four  trees. 

The  varieties  in  the  experimental  plots  in  this  orchard  were 
Fall  Pippin,  Mcintosh  and  Greening.  Each  variety  was  repre- 
sented in  the  spray,  dust  and  check  plots,  except  that  there  were 


234  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  245. 

no  Fall  Pippins  in  the  check  plot.  Count  trees  were  selected  soon 
after  blooming  and  trees  that  gave  promise  of  having  a  good  crop 
were  selected.  Two  trees  of  each  variety  were  selected  in  each 
plot,  one  receiving  the  five  treatments  and  the  other  the  three 
treatments. 

The  number  and  dates  of  application  were  the  same  as  those  in 
orchard  No.  I.  The  owner  of  the  orchard  put  on  the  regular  de- 
layed dormant  spray  over  all  the  plots,  also  the  pre-pink  spray  on 
all  Fall  Pippin  and  Mcintosh  trees.  The  regular  spraying  and  dust- 
ing operations  began  with  the  pink  treatment  on  April  28,  followed 
by  the  calyx  application  on  May  19.  The  first  treatment  after  the 
calyx  was  applied  on  June  13.  After  this  treatment  the  spray  and 
dust  plots  were  divided  into  two  parts,  one  part  of  which  receiv- 
ed two  further  applications  of  spray  and  dust,  while  the  other 
had  no  further  treatment. 

In  this  orchard  the  liquid  spray  was  put  on  with  a  Friend  power 
sprayer,  using  two  lines  of  hose  with  two  nozzles  at  each  rod.  One 
man  sprayed  the  tops  of  the  trees  from  a  tower  on  the  spray  out- 
fit while  the  other  sprayed  the  lower  part  of  the  tree  from  the 
ground.  The  regular  lime-sulphur  arsenate  of  lead  spray  with  the 
addition  of  Black  Leaf  40  was  used. 

The  dust  Was  applied  with  the  same  duster  used  in  the  other 
orchard.  Only  one  kind  of  dust  was  used  in  this  orchard,  namely, 
the  sulphur-nicotine  dust.  About  three  or  four  pounds  of  dust 
were  used  per  tree. 


Table  No. 

II. 

t 

Results 

of  Treatment.     Greening. 

J3 

CO 

•  fM 

O 

0 

ho 

+j 

4-J 

hn"*"* 

gj 

r\  ■** 

CD 
to     . 

+j 

a 

3  -m 

a 

V 

a 

CD 

,5  v 

|-8 

M    ID 

a 

CD 

M    CD 

TJU 

.20 

By 

2U 

gu 

CD  w 

.*,<-> 

CD  ^ 

0   u 

■fl  u 

t>    u 

"O  u 

1-  u 

JZ   !- 

rt  *-< 

J3  u 

O    CD 

Oh   (U 

CD    CD 

O    V 

3  dj 

-M    CD 

CJ    CD 

-u    CD 

Treatment. 

OFM 

<Ph 

«Ph 

UfL, 

UPh 

OPh 

C/}Ph 

OPh 

Spray, 

5    applications    .... 

51.2. 

1.3-7 

i-7 

.14 

i5-i 

1.76 

28.1 

6.45 

Sul.-Nic.-Ars.  Dust, 

5    applications    . .  . 

7.8 

7-77 

•34 

.42 

7-5 

2.36 

46.2 

.97- 

0 

26.7 

16.4 

21.2 

76. 

6.62 

89.5 

113. 

Spray, 

3    applications    .... 

60.5 

9.02 

•05 

.48 

6.2 

•97 

16.5 

12.9 

Sul.-Nic.-Ars.  Dust, 

3    applications    . .  . 

6.4 

11.04 

.68 

■76 

IS- 

6.5 

54-2 

108.4 

DISCUSSION    OF   RESULTS. 


From  Table  II  it  is  very  evident  that  the  liquid  spray  both  in 
five  and  three  applications  gave  a  much  higher  percentage  of  good 
fruit  than  the  dust  treatment.  The  difference  in  control  of  apple 
scab  and  other  fungous  diseases  is  marked.  In  the  control  of  in- 


RESULTS  OF  DUSTING  VERSUS  SPRAYING  IN  CONNECTICUT.     235 

sect  pests,  the  difference  is  not  as  great,  although  still  a  little  in 
favor  of  the  liquid  spray.  The  value  of  five  over  three  applica- 
tions in  both  dust  and  liquid  spray  is  again  shown,  especially  in 
the  case  of  other  insects  and  other  fungi,  which  appear  later  in  the 
summer  and  are  controlled  with  later  applications. 

Table  No.  III. 

Results  of  Treatment.     McIntosh. 


c 

c 

V 

0 

bo  c 
c  "J 

si 

c  c 

V 

c 

T)U 

«u 

t"?U 

J:<-> 

3^ 

£U 

„u 

SjU 

8  u 

'■£  k. 

T3  u 

-a  u 

>- 1* 

J3  1- 

rt  •- 

—     Vh 

Treatment. 

O    tU 

OPh 

«Ph 

0  <u 
UP-< 

5  i> 

5  u 
c/iP-i 

OCL, 

Spray,  _ 

5    applications    .... 

40. 

5-27 

•44 

•34 

2.8 

•54 

54-5 

4.38 

Sul.-Nic.-Ars.  Dust 

5    applications    .... 

6.39 

9-54 

.09 

.18 

3.56 

.647 

86.4 

•55 

Checks    

.121 

2.9 
.026 

78 
.227 

4.4 
.06 

35-3 
2.26 

3-H 
1.74 

98.4 

54-7 

9.11 
.166 

Spray, 

3    applications    . .  . 

44.4 

Sul.-Nic.-Ars.  Dust, 

3    applications    .... 

5.06 

3.58 

.117 

•3ii 

4.66 

i-55 

96. 

2.62 

DISCUSSION    OF   RESULTS. 

Here  the  liquid  spray  is  again  better  than  the  dust  treatments, 
particularly  in  the  control  of  scab.  The  percentage  of  good  fruit 
is  very  much  greater  in  the  sprayed  plots  both  for  the  three  and 
five  treatments  than  in  dusted  plots.  In  control  of  other  pests,  the 
difference  is  not  so  marked.  The  difference  noted  in  control  of 
fungi  on  Greenings  is  more  evident  than  in  the  case  of  Mcintosh, 
probably  because  the  Mcintosh  does  not  seem  to  be  so  susceptible 
to  these  diseases,  as  the  check  plot  shows  only  nine  per  cent,  of 
injury  in  this  column. 

Table  No.  IV. 
Results  of  Treatment.    Fall  Pippin. 


Treatment. 

Spray, 

5    applications 

Sul.-Nic.-Ars.  Dust, 

5   applications 

Spray, 

3  applications 

Sul.-Nic.-Ars.  Dust, 

3    applications 

No  checks. 


-dU  .S£U 

O     <D  Oh   1) 

00,       <p< 


24.9  1 4. 1 

2.61  6.28 

19.09  12.9 

•95  II- 


•d  u 
«PM 


•31 

■23 

.6 
.08 


o 

•a  k 

O    <L> 

UPh 


3  <u 


•e  1- 

X  v 
OPj 


c 

IflPn 


bo 

C     . 
3  *> 

—  Ui 
OP* 


.387  2.56  1.35    64.4  6. 

.326  5-62  1.44    94-5  23. 

■247  3-99  -846  79-5  6.6 

.52  6.4  1.95     94-9  48.6 


236  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  245. 

DISCUSSION    OF    RESULTS. 

The  results  in  the  Fall  Pippin  plot  are  similar  to  those  obtained 
in  the  other  plots,  the  liquid  spray  again  giving  a  higher  percentage 
of  good  fruit  and  a  very  much  lower  percentage  of  scabby  fruit 
also  a  much  lower  percentage  of  fruit  showing  the  injury  of  sooty 
blotch  and  fruit  speck.  The  differences  in  control  of  insect  pests 
are  not  so  evident  as  in  the  case  of  fungous  diseases.  There  were 
no  check  trees  left  in  the  Fall  Pippin  plots,  but  in  preceding  years 
the  fruit  was  absolutely  worthless,  showing  nearly  ioo  per  cent, 
of  scab. 

ORCHARD    NO.    III. 

This  orchard  is  located  two  miles  north  of  the  village  of  Mil- 
ford  and  is  bounded  on  the  east  side  by  a  highway  running  north 
and  south.  The  trees  are  18  years  old,  and  are  located  on  a  fairly 
level  piece  of  land  with  woods  on  the  west  and  open  fields  on 
north  and  south  sides.  The  trees  had  dense  crowns,  making  it 
rather  difficult  to  reach  the  centers  with  spray  or  dust. 

The  varieties  used  in  the  experimental  work  in  this  orchard 
were  Baldwin,  Greening,  Gravenstein  and  Mcintosh.  This  or- 
chard was  divided  into  four  plots,  one  for  liquid  spray,  two  for 
dust  and  one  for  check.  Two  kinds  of  dust  were  used,  Sanders  or 
copper  dust,  and  sulphur-nicotine-arsenate  dust.  Count  trees  were 
selected  soon  after  blossoming,  and  the  green  dropped  fruit  from 
them  gathered,  counted  and  scored  twice  during  the  summer.  At 
harvest  time  the  fruit  remaining  on  these  trees  was  gathered  and 
scored. 

'  The  applications  of  spray  and  dust  were  put  on  at  approximate- 
ly the  same  dates  as  those  of  Orchard  No.  II.  This  orchard  had 
no  delayed  dormant  treatment  nor  any  pre-pink  spray,  the  first 
being  applied  when  the  blossom  clusters  had  separated  and  were 
showing  pink.  As  in  the  other  two  orchards  the  spray  and  dust 
plots  were  divided  after  the  third  application,  one-half  of  each 
receiving  two  more  treatments,  while  the  other  had  no  further  ap- 
plications. 

The  spray  outfit  used  here  was  also  a  Friend  machine,  but  a 
spray  gun  was  used  instead  of  spray  rod  as  in  orchard  No.  II.  The 
same  duster  was  used  here  as  in  the  other  orchards.  The  dusting 
was  always  done  on  the  same  day  and  usually  before  the  spray 
was  applied.  One  day  the  wind  was  too  strong  for  dusting,  so 
that  it  had  to  be  put  off  until  the  evening  of  that  day. 


RESULTS  OF  DUSTING  VERSUS  SPRAYING  IN  CONNECTICUT.     237 


Table  No.  V. 
Results  of  Treatment.     Baldwin. 


-*J 

hn-H 

0 

rt  -*-* 

U 

an 

c 

3-W 

a 

a 

3   C 

be  C 

.2  c 

mC 

a 

fa  C 

<u 

<D 

<K   ^ 

c  "J 

*3    D 

ID 

<u 

«j 

X}U 

.20 

PQcj 

3U 

3^ 

.ou 

0   V. 

•S  u 

T3  in 

13  v. 

h    *- 

a:  ■- 

as  >-< 

J3  h 

0   V 

—  OJ 

Cj    (U 

0  1) 

3  <u 

-u    (U 

<j  <u 

-t-J    (L) 

Treatment 

Ufa 

<fa 

fafa 

Ufa 

Ufa 

OP, 

Cflfa 

Ofa 

Spray, 

_5  applications  .... 

39-2 

28.2 

i-53 

.338 

20.77 

1.6 

■73 

9.96 

Sul.-Nic.-Ars.  Dust, 

5  applications   .... 

ii-S 

8.1 

•675 

•725 

24.87 

3- 

.948 

1 17.2 

Sanders  Dust, 

5  applications   .... 

21.5 

11.6 

2.55 

1.03 

40.64 

6.73 

.222 

52.2 

Checks    

0 

51-72 

7.16 

24.88 

93-6 

24.8 

.127 

177-5 

Spray, 

_-(-._ 

/  /     %J 

3  applications   .... 

25.8 

I5-I 

4.1 

I-I5 

36.22 

3-73 

.823 

58.68 

Sul.-Nic.-Ars.  Dust, 

2.48 

10.7 

1.8 

1. 11 

47-65 

4.71 

1.07 

H6.5 

Sanders  Dust, 

3  applications  .... 

5-9 

19-95 

i-39 

.856 

51-55 

6.66 

•45 

149.8 

DISCUSSION  OF  RESULTS. 

In  each  case  the  liquid  spray  produced  a  higher  percentage  of 
good  fruit;  Sanders  dust  came  next  and  sulphur-nicotine-arsen- 
ate  dust  last,  with  the  exception  of  the  check  plot,  which  had  no 
good  fruit  at  all.  In  the  case  of  fungi,  spray  was  best,  Sanders  dust 
averaged  second  best,  while  sulphur-nicotine-arsenate  dust  was 
third.  In  control  of  aphis  and  red  bug,  either  of  the  dusts  were 
better  than  the  liquid  spray  and  the  sulphur-nicotine-arsenate  dust 
was  better  than  the  Sanders  dust. 

In  controlling  curculio,  codling  moth  and  other  chewing  in- 
sects, liquid  spray  was  a  little  better  than  either  dust.  There  was 
little  difference  between  the  two  dusts  for  the  control  of  other 
insects. 

Table  No.  VI. 
Results  of  Treatment.    Greening. 


+j 

hn-*-* 

0 

0  ^ 

O 
OJ 

+j 

bo 

s    . 
3  +1 

c 

a 

00     r- 

QO  C 

.2  c 

M    C 

£ 

fa  ?, 

tu 

V 

.5    OJ 

C    v 

t~  aj 

V 

OJ 

O 

•oU 

w(J 

PQU 

£0 

3" 

■-CJ 

,nU 

•-U 

0  ■_ 

•s  ^ 

13  u 

13  u 

1-  u 

.C      lH 

ra  I- 

.S  u 

O   (U 

0-  <u 

<U    QJ 

O    OJ 

3  <u 

+J    OJ 

u  <u 

+J    QJ 

Treatment. 

Ufa 

<fa 

fafa 

Ufa 

Ufa 

Ofa 

MP, 

Ofa 

Spray, 

5  applications   .... 

39-6 

38.2 

2.14" 

•279 

14.02 

1.02 

12.31 

10.38 

Sul.-Nic.-Ars.  Dust, 

5  applications   .... 

n.85 

22. 

•44 

2.2 

27.2 

1.97 

39-1 

86.5 

Sanders  Dust, 

5  applications 

16.8 

14-5 

3.89 

6-73 

45.22 

8.42 

33-35 

36.1 

0 

16.85 

50.5 

22.79 

99- 

28.75 

45-6 

184. 

Spray,_ 

3  applications   .... 

18.3 

29.8 

1.9 

1-737 

25-34 

2.56 

30.95 

63.1 

Sul.-Nic.-Ars.  Dust, 

3  applications  

i-35 

17.9 

•579 

i-35 

39-55 

4.8l 

39-i 

140.7 

Sanders  Dust, 

3  applications  .... 

.586 

25-7 

14-35 

6.23 

53-8 

9-75 

30.65 

180.87 

238  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  245. 

DISCUSSION  OF  RESULTS. 

In  the  Greening  plots  the  liquid  spray  is  again  better  than  either 
of  the  dusts.  The  three  treatments  of  spray  gave  a  higher  per- 
centage of  good  fruit  than  five  applications  of  either  dust.  For 
some  reason  the  three  treatment  Sanders  dust  plot  made  the  poor- 
est showing  both  in  the  percentage  of  good  fruit  and  percentage 
of  other  fungi.  The  sulphur-nicotine-arsenate  dust  appeared  to  be 
more  effective  in  controlling  aphis  and  red  bug  than  either  spray 
or  Sanders  dust. 


Table  No.  VII. 
Results  of-  Treatment.     Gravenstein. 


■*j 

-M 

hn-*-* 

0 

0  -*-1 

O 
If)      • 

-M 

a 

a 

3    c 

bo  C 

.2  a 

w  c 

G 

^  s 

<u 

<v 

£   v 

c  v 

-.    u 

(D 

OJ 

(U 

T)U 

.2U 

«u 

su 

3u 

^u 

til 

O    u 

■S  u 

•O  u 

T3    u 

1-  u 

•C  I-. 

ra  ^ 

J3  v. 

O    V 

q,  d 

QJ    OJ 

O    <U 

3  <U 

+j    tu 

CJ  <u 

^    <L> 

Treatment. 

OPh 

<Ph 

P^P-I 

UPh 

UPh 

OPh 

[/)Ph 

OPh 

Spray, 

5  applications   ..... 

46.4 

25-3 

1.82 

.032 

10-73 

1.4 

17.98 

6.65 

Sul.-Nic.-Ars.  Dust, 

5  applications   

8.4 

18.2 

i-5i 

•331 

32.43 

2.97 

56.6 

51-55 

Sanders  Dust, 

5  applications   

14. 1 

28.7 

3-55 

•935 

39-59 

5-32 

42-35 

10.8 

Checks    

.04 

27.9 

6-55 

•63 

56.25 

3-95 

28.34 

54-2 

Spray, 

"WT 

/     -y 

3  applications  .... 

31.2 

34- 

2.69 

.018 

10.32 

i-95 

25-77 

19.64 

Sul.-Nic.-Ars.  Dust, 

3  applications  .... 

6.77 

12.9 

•415 

.192 

30.79 

3-7 

64.6 

135-5 

Sanders  Dust, 

3  applications   

10.9 

19.1 

1.28 

•39 

43-94 

5-03 

42.8 

29.4 

DISCUSSION  OF  RESULTS. 

It  will  be  seen  from  Table  VII  that  the  liquid  spray  gave  better 
control  of  scab  and  other  fungous  diseases  than  did  either  of  the 
dusts.  The  Sanders  or  copper  dust  gave  a  higher  percentage  of 
good  fruit  and  a  lower  percentage  of  scab  and  other  fungi  than 
the  sulphur-nicotine-arsenate  dust.  As  might  be  expected,  the  nic- 
otine dust  gave  better  control  of  sucking  insects  such  as  aphids 
and  red  bugs  than  the  Sanders  dust.  It  was  also  a  little  better  in 
controlling  curculio  and  other  chewing  insects. 


RESULTS  OF  DUSTING  VERSUS  SPRAYING  IN  CONNECTICUT.     239 

Table  No.  VIII. 
Results  of  Treatment.     McIntosh. 


a 

<u 


3g 

flU  .20         «u 

Treatment.  OPm  <£l,  «Cl, 

Spray, 

5  applications  28.2         2.56       1.94 

S11l.-Nic.-Ars.  Dust, 

5  applications   ....        1.85       9.71       3.62 

Sanders  Dust, 

5  applications 238  11.2       18.3 

Checks    601   10.75     13-4 

Spray, 

3  applications  4.73       9.1         5.61 

Sul.-Nic.-Ars.  Dust. 

3  applications 11     13.3         5.71 

Sanders  Dust, 

3  applications 364     8.65     13. 


0 

•O  u 

O    OJ 

Ufc 

.2  c 

l-  u 

0 

M  s 

J3  u 
X  v 
O0< 

a 

u 

0  V 
C/lP-i 

Other  Fung 
Per  Cent. 

.08s 

14.21 

1.44 

66.2 

I.46 

.362 

9.2 

1.49 

97.2 

5- 

•315 

27-45 

.3-42 

96.3 

3-74 

1-35 

9-34 

•975  98.9 

2.29 

•391 

H-53 

1.07 

934 

548 

■33 

13-52 

1.65 

99-8 

5-27 

•5 

25-34 

3-28 

99.1 

8.7 

DISCUSSION  OF  RESULTS. 

The  results  of  the  treatments  are  similar  to  those  obtained  in 
the  other  varieties,  the  liquid  spray  again  giving  the  best  results 
and  the  Sanders  dust  being  a  little  better  for  control  of  fungous 
diseases  than  the  sulphur-nicotine-arsenate  dust.  The  check  tree 
of  this  variety  was  located  in  the  spray  plot  and  was  partly  sprayed 
twice.  This  probably  accounts  for  the  low  percentage  of  in- 
jury when  compared  with  the  other  treatments. 


Table  No.  IX. 

Results  of  Treatment.    Commercial  Grading. 

Grade  No.  I  Grade  No.  II 

Treatment                                                                            Pt  Cent.  Per  Cent. 

Baldwin. 

Spray    ........ 41.05  40-95 

Sulphur-nicotine-arsenate  dust    ....             37.1  45-25 

Sanders  dust 34-65  46.4 

Check   0  0 

Greening. 

Spray    ; 59.45  20.8 

Sulphur-nicotine-arsenate  dust   48.1  38.1 

Sanders  dust  3445  35- 

Check   0  o 

Gravenstein. 

Spray    85.1  10.9 

Sulphur-nicotine-arsenate  dust    ....             67.6  26.8 

Sanders  dust  78.  19-95 

Check 0  57. 


Culls 
Per  Cent. 


18. 

17-65 
18.95 
100. 


19-75 
13-8 

30-55 
100. 


4- 

5-6 

2.05 

43- 


24O  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  245. 

McIntosh. 

Spray 63.75  27.50  8.75 

Sulphur-nicotine-arsenate  dust    ....  Not  graded. 

Sanders  dust  19.  42.  39. 

Check     Not  graded. 

DISCUSSION  OF  RESULTS  OF  COMMERCIAL  GRADING. 

This  method  of  obtaining  data  shows  that  the  liquid  spray  is 
superior  to  either  of  the  dusts  used  in  orchard  No.  III.  This  is 
true  of  each  of  the  four  varieties  in  the  experimental  plots,  in 
each  case  producing  a  higher  percentage  of  No.  I  fruit.  In  the 
Baldwin  and  Greening  plots  the  sulphur-nicotine-arsenate  dust 
produced  a  greater  percentage  of  No.  I  apples  than  the  Sanders 
dust,  though  in  the  case  of  Gravensteins,  the  Sanders  dust  showed 
up  the  best.  Due  to  an  oversight  the  fruit  from  the  Mcintosh  sul- 
phur-nicotine-arsenate dust  plot  was  not  graded,  so  that  no  com- 
parisons can  be  made. 

ORCHARD   NO.   IV. 

This  is  the  old  orchard  on  the  Experiment  Station  Farm  at 
Mount  Carmel.  This  orchard  is  46  years  old  and  consists  of  about 
40  Baldwin  and  Greening  trees  planted  rather  closely  together. 
This  orchard  was  divided  into  halves.  The  east  half  was  used  for 
the  sulphur-nicotine-arsenate  dust  plot  and  the  west  half  for 
Sanders  dust.  One  row  along  the  north  end  of  the  orchard  was 
left  for  a  check.  Count  trees  in  each  plot  were  selected  early  in 
the  season,  but  in  this  orchard  the  early  dropped  fruit  was  not 
gathered  and  scored.  No  scoring  was  done  until  harvest  time, 
then  all  the  fruit  from  two  trees  in  each  plot  was  picked,  scored 
and  then  graded  commercially  into  three  grades,  No.  I,  No.  II  and 
culls. 

No  liquid  summer  spray  was  used  in  this  orchard  and  only  two 
kinds  of  dust,  namely:  sulphur-nicotine-arsenate  and  Sanders  or 
copper  dust.  The  entire  orchard  was  sprayed  with  the  regular  de- 
layed dormant  spray  of  commercial  lime-sulphur,  one  part  to  nine 
of  water.  This  was  applied  on  April  11  and  12. 

The  first  application  was  made  on  April  29,  when  the  blossom 
buds  began  to  show  pink.  The  next  treatment  was  the  calyx  ap- 
plication on  May  22.  This  orchard  received  only  one  more  appli- 
cation of  dust  and  that  was  on  June  14. 

The  dust  at  each  treatment  was  applied  early  in  the  morning 
before  the  dew  was  off  the  leaves.  There  was  very  little  fruit  on 
the  check  trees  at  the  time  of  harvest  and  none  was  scored  or  grad- 
ed. The  work  in  this  orchard  was  simply  a  comparison  of  the  two 
dusts  used. 


RESULTS  OF  DUSTING  VERSUS  SPRAYING  IN  CONNECTICUT.     24I 


Table  No.  X. 
Results  of  Treatment. 


Baldwin. 


g 

V 

•oU 

O    !_ 

OP4 


Treatment. 
Sul.-Nic.-Ars.  Dust.     30.2 
Sanders  dust  31.8 


—  _ 
<Ph 

20.5 

18.1 


fflu 
•o  u 

PS  PL, 


S~ 


bo 

C 


be  c 

.2  = 

5g 

c 

fe  c 

3U 

■3  K 

V 

Su 

fe« 

.n.9 

53  <-> 

T3  u 

V-  ;-, 

J3   1- 

rt  u 

•C   U 

0  <u 

3  <u 

*J    CJ 

0  « 

<t->    O 

UPm 

UPh 

OPh 

C/2CL, 

OPh 

.087 


1.03   29.54 
2.53   23.14 


4.09 

5-03 


.148 


5i-7 
46.7 


DISCUSSION  OF  RESULTS. 


In  this  orchard  there  was  very  little  difference  between  the  two 
kinds  of  dust.  The  percentage  of  good  fruit  was  very  nearly  the 
same,  while  in  the  control  of  fungi  the  Sanders  dust  gave  slightly 
better  results.  The  other  differences  are  so  slight  that  they  are 
hardly  worth  mentioning. 

Table  No.  XL 

Results  of  Treatment.    Greening. 


Treatment. 

Sul.-Nic.-Ars.  Dust. 
Sanders  dust  


c 

v 

2  <- 

OPh 

18.05 

22.5 


B 

•5  t- 

<Ph 
20. 
35-8 


J3      " 

en 

^ 

O 

u 

'bo 

bo-" 

^^ 

,-,  -M 

-M 

a 
s-i-r 

3  C 

be  c 

.2  c 

m  c 

C 

tin  C 

03  v 

4) 

-O  u 

"O   h 

v.   In 

•C    1- 

a  »-« 

-=  u 

V    <J 

O   OJ 

3  <u 

<-•  0 

0  <u 

-w  CD 

PSPm 

Oft 

Uft 

CPh 

cflft 

OPh 

.056 

3-77 

45-2 

3-71 

2.08 

85-72 

7-37 

44.04 

4-1 

•504 

48.27 

DISCUSSION  OF  RESULTS. 


The  Sanders  dust  again  gave  better  control  of  fungous  diseases 
and  consequently  produced  a  higher  percentage  of  good  fruit.  The 
sulphur-nicotine-arsenate  dust  gave  better  control  of  aphis  and 
slightly  better  control  of  other  chewing  insects. 


Table  No.  XII. 
Results  of  Treatment.    Commercial  Grading. 


Treatment 

Baldwin. 

Sulphur-nicotine-arsenate  dust 
Sanders  dust  , 


Grade  No.  I 
Per  Cent. 

Grade  No.  II 
Per  Cent. 

Culls 
Per  Cent. 

6l. 

53-6 

26.I 

35-6 

I3-I 
10.7 

55-5 
52.2 

29-7 

27-3 

14.8 
20.4 

Greenings. 
Sulphur-nicotine-arsenate  dust  .... 
Sanders  dust  


By  the  commercial  grading  method  of  taking  results  the  sul- 
phur-nicotine-arsenate dust  gives  the  highest  percentage  of  No.  I 
fruit.  The  fungous  troubles  (best  controlled  by  Sanders  dust) 
were  apparently  light  enough  to  permit  fruit  showing  their  char- 


242  CONNECTICUT  EXPERIMENT  STATION  BULLETIN  245. 

acteristic  injury  to  be  placed  in  a  No.  I  grade  and  some  of  the 
fruit  scored  as  "good"  by  the  other  method  of  taking  results  may 
have  been  too  small  to  go  into  this  grade. 

PEACH  ORCHARDS. 

Dusting  versus  spraying  to  control  peach  scab  and  brown  rot 
was  continued  in  the  same  orchards  and  with  the  same  number  of 
trees  as  in  1921.  Dusting  sulphur  without  lead  arsenate,  and 
■"Atomic  Sulphur,"  at  the  rate  of  10  pounds  to  100  gallons  of  water 
were  the  materials  applied  in  both  orchards. 

Orchard  No.     I.     Peach     orchard     of     M.     L.     Coleman, 

Cheshire    - 113  trees 

Orchard  No.  II.     Station  peach  orchard  Mount  Carmel...      150  trees 


263  trees 

The  dust  was  applied  with  a  Niagara  duster  and  the  spray  with 
an  Arlington  X.  L.  sprayer  in  both  orchards.  The  picked  fruit 
only  was  scored.  This  involved  the  counting  and  scoring  of  41,980 
peaches  or  about  600  baskets.  Four  applications  were  made  on  the 
following  dates  :  May  29,  June  22,  July  11  and  August  1.  The  re- 
sults of  the  treatments  are  shown  in  Table  No.  XIII. 

Table  No.  XIII. 
Results  of  Treatment  in  Peach  Orchard  No.  I. 

Good  Rot  Scab 

Per  Cent.  Per  Cent.  Per  Cent. 

[  Spray 71  10  13 

Elberta  <(  Dust    66  17  13 

[  Check    20  20  62 

f  Spray    69  5  18 

Carman  -J  Dust    65  7  17 

[  Check   32  21  50 

The  last  treatment  was  applied  to  only  one-half  of  each  plot  and 
showed  no  advantage  over  the  three  treatments. 

It  will  be  seen  from  the  table  that  the  spray  controlled  the 
brown  rot  slightly  better  than  the  dust,  and  scab  control  was  prac- 
tically the  same  for  both  treatments. 

Table  No.  XIV. 
Results  of  Treatment  in  Peach  Orchard  No.  II. 

Good  Rot 

Per  Cent.  Per  Cent. 

Elberta       \  ^ra/ 97  3 

(  Dust     99  1 

Champion(Sp™y    ..............  I  ^ 

In  Orchard  No.  II  the  dust  controlled  the  brown  rot  better  than 
the  spray  on  both  Elberta  and  Champion  varieties.  There  was  no 


RESULTS  OF  DUSTING  VERSUS  SPRAYING  IN  CONNECTICUT.     243 

scab  in  this  orchard  either  on  treated  or  untreated  trees.  The  data 
for  the  check  trees  are  not  given  because  these  trees  were  adja- 
cent to  the  treated  trees  and  the  dust  was  blown  upon  the  checks, 
controlling  the  rot  nearly  as  well  as  upon  the  trees  dusted  directly. 

SUMMARY. 

i.  In  all  apple  orchards  and  on  all  varieties  used  in  these  ex- 
periments, liquid  spray  gave  better  results  than  any  kind  of  dust 
used. 

2.  By  the  commercial  grading  method  of  taking  results,  sul- 
phur-nicotine-arsenate  dust  gave  a  higher  percentage  of  No.  I 
fruit  than  Sanders  dust.  By  the  other  method  of  scoring  each 
individual  apple,  Sanders  dust  usually  gave  a  higher  percentage 
of  perfect  fruit  than  sulphur-nicotine-arsenate  dust. 

3.  Sulphur-nicotine-arsenate  dust  gave  decidedly  better  results 
in  controlling  aphids  and  red  bugs,  and  slightly  better  results  in 
controlling  curculio,  codling  moth  and  other  chewing  insects  than 
Sanders  dust. 

4.  Sanders  dust  gave  very  much  better  results  in  controlling 
apple  scab  and  other  fungous  diseases  than  sulphur-nicotine-arsen- 
ate dust. 

5.  Liquid  spray  was  best  for  controlling  most  pests  except 
that  sulphur-nicotine-arsenate  dust  was  nearly  as  good  for  control 
of  aphids  and  red  bugs. 

6.  Where  fungous  diseases  are  not  likely  to  be  present  a  fair 
grade  of  commercial  fruit  may  be  secured  by  use  of  dusts,  but 
where  the  highest  grade  of  apples  is  desired,  liquid  spray  may  be 
relied  upon  to  give  best  results. 

7.  The  brown  rot  and  scab  of  peaches  were  controlled  just  as 
well  by  sulphur  dust  as  by  a  spray  of  "Atomic  Sulphur." 


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